People Can't Connect To My Server Anymore. Please help!

so recently I was hosting a minecraft server and everyone thing was going good, people were able to connect, but then I starting getting some out of memory errors, and I installed a new version of java, and now people aren't able to connect to my server through my external ip, and i haven't changed any of my router settings anything. The weird thing is that I cant still connect through my ipv4 but not my external ip. So if you know anything that could fix this please help.